Screw-thread-cutting device



T. SHEHAN. SCREW THREAD CUTIING DEVICE. APPLICATION'FILED AUG.25, m9.

1,391,514. v PatgntedSept- 20,1921.

hi ff-Horne UNITED STATES THOMAS SHEHAN, OF CIiEvELAl TD, OHIO. V

' scREw-TnREAD oUT'rING DEVICE.

,T all whom it may concern.

Be ittknown that I, THOMAS S EHlm, a

citizen of the United States, residing at Cleveland,, in the county of Cuyahoga and State of Ohio, have invented a new and use ful Screw-Thread-Cutting Device, of which the following is a specification. r

This invention relates to lmprovements n up devicesfor cutting screw -threads andmore' iespeciallyto a" device comprising a cutter;

head which has acent'rally located bore extending to the forward face of the cutterhead and is provided in its forward portion with radially arranged slideways which are spaced circumferentially of said bore and engaged by slides carrying cutters for outvtin screw-threads.

y (Sue object of this invention'lsto provide any improved"v application ,-'of" the cuttersj which are reversible end for end.

Another-object is not only to removably [secure eachcutter. to the slidecarrying said cutter by a screw whichlis c'onveniently a c-' cessible,fbut to prevent any stra n upon said screw during operation of the cutter.

Q Another object is to permit exposureof I the cutters and the cutter-carrying slides at v the forward face of the cutter-head and to prevent displacement ofsaid slides 'forwardly from the cutter-head. 1

Another. object is to provide an improved j operative connection between each cutter carrying sl1de and the crank of a crankshaft which has bearing in the cutter-head and is employed in shifting or adjusting said slide radially of the cutter-head.

Another-object. is to render each cutter Q readily replaceable by another cutter.

Withthese objects in view, and to attain any other obj ect'hereinafter appear ng, thisinvention consists in certain features of construction, flIldKCOInblIltttlOIlS andrela tive arrangements of parts, hereinafter described fin this specification, pointed out in the 1 claims, and illustrated in the accompanying. I drawings,

In said drawings, Figurel iisia front end viewof the forward end portion of'a cutterhead embodying my invention. 7 Fig.2 is an enlarged viewof a portion of: Fig. 1. Fig. 3 isa vertical section taken along the line i 7 3+3, Fig. 2, looking in the direction indi- 'cated by the arrow. Fig. 4 is a' horizontal section taken along theline Fig; 2,

looking downwardly. Fig. 5 "is a trans- Specification of Letters Patent.. Pat

spaced equidistantly circumferentiallyof a tedSjept. 192 1.

Application filed u ust 25, 1919.;Serial"1'o. 319,711..

verse vertical s'ection'taken alongthe line 5-5, Fig.3, looking in the direction indicated by the arrow. Fig. ,6 is alongitudinal' central sectlon of a detached cutter-carryino' sl1de. T I 7' lteferrin'g to said. drawings,;10 indicates are. arranged radially ofth'e cutterhead and bore; 13 formed in} any approved manner centrally and extendin .endwise of the cutt er head fanditojfs'aid ace.. Each slideway 12 is engaged by alslide 14 carrying a cutter and extends from .thefbore 13 to the outer, c rcumferentlalsurface of the cutter-head."

slideway12has its: rearward portion .la'rger'inwidth than. the remainder offthe slideway (see Figi). so .as to formtwo rearf wardly facing shoulders 16: arranged at opposite sldes respectively of the slideway,

nd the slide'engaging said slideway has portions 17 thereof overlapping said shoul-, 'ders. Obviously said shoulders and the shoulder-overlapping portions of said slide prevent displacement of the slide forwardly from the cutter-head. .Each' slidelt is of course shiftable ,endwise of the-engaging slideway. I

Eachslide lt ('see Figs. 1, 2 and 3 is shown provided, in its forward portion, and

centrally between its sides, with a recess 18 which is engaged. by the cutter carried by said slide' and extends'longitudinally, and from-end to end of the slide and to theface of the cutter-head, and said'cutter extends "endwlse of the recess.

, The end the recess 18 in each slide (see 'ortions of ig. 6) extend, as at 19,to, the rear side of the slide. Each cutter (see Figs. 4, 5 and 6) is pro,- vided at its rearside with a recess 20 which extends longitudinally of the cutter andis arranged 14 is provided at its rear side (see'Figs. .4 and 6) with a slideway 22 arranged centrally between the ends and extendingtransversely of and through the-slide. Each slide -141 has a screw-threadedhde 23"arr'anged a cutter he'ad which (see 1* ig. is provided at its'forwa'rdface with slideways 12jwhich right angle to the slideway l2 engaged by Bald slide. To facilitate the making of my improved screw-th'read cutting device each 7 cutter is provided with a hole 24 which is arranged in line endwise and consequently registers with the hole 23 inthe associated slide and extends to the forward side of the cutter andis enlarged in'diameter, as at 25,

v at its forward end, and a screwhas its shank '26 extending loosely throughsaid hole 24 v in said cutter and threaded into said slide at'the aforesaid hole 23 in the slide. Said screw removably secures the associated cuttertofthe'slide carrying thecutter and hasitshead 27 occupying the aforesaid enlar ed" 'end'25 of the hole 24: in said cutter. 'theconstru'ction hereinbefore described it "will be observed that eachslideway 12 extends radially of the cutter-head at the forward face of the cutter-head and is engaged by a slide'exposed at saidface, thatv the cutter "associated with said slide is secured to the slide'by a screw having its head exposed at said face, and that said slide has a portion thereof arranged to form' abutments for the walls 'of'the recess in said cutter so that strain on said screw, during the [operation f thecutter, is positively and inexpensively avoided.

' I would 'also remarkjthat each cutter has thread-cutting teeth 28 ateach end and-is 'reversible'end for end, and it"will be observedthat said cutter, being securedto the 7 associated slide by a screw having its head "head, is readily detachablefrom the slide to exposed at the forwardface of 'the cutterreverse it end for end.

j The slideway 22,111 each seam is ar-i rang'edsubstantially at, a rightangle to the Said slideway 12 engaged by said slide 1 slideway 22in each slide (see Figs. 2, 3 and endwise of the slideway and provided with a c'entral'fhole, 31 which extends forwardly from the rear face of said block substantially said slide, "and a' shaft 32, which h Sj 4:) is engaged by a block 30 which is movable am right angle to theslideway '12 engaged ing in the cutter-head at the rear sideof said slidewa'y 22 in said slideand is substantially parallel with "said; hole, has-a crank 33 loosely fittingfsaid'hole and forming a pivi'f said'shaft between the shaft "and the afore a I ItI will be observed therefore th'atthe operative'connection between a cutter 1 -5 the shaft32 assoeiatedwith said cuttencomprises opposite side wallsflofjthe sl1'deway22jin the slide carrying said cutter f and'Jthe -blockBO which engages saidfslide-l f o'f 'the' cutter and has fits end ;Wallsover-, 1 '1 way and embraces the 33 'of said shaft,

and said block therefore forms a desirably large bearing between said'crank and said slide. quently the cutter carried by said slide, are actuated endwise inwardly 'or outwardly according as the associated 'crank-shaft32 is rotated in the one or the otherdirection.

All of the shafts employedin the actua- Obviously each slide 14, and consey tion of the cutter-carrying slides are prefers ably rotated simultaneously, but means rm simultaneously and correspondingly rotat ing shafts employed in readjusting-pr "actuating cutters endwise, and means for'loc'king'said' shafts in the desired adjilstinentf'of v the cutters, are too well knownin the .artjto require description and illustration this specification.

The cutters are shown in Fig. 1 as' ini posi tion ready for operation on and externally of apiece of work (not shown) to beintroduced between the inner ends of the cutters and to be operated on bythe thread-cutting l teeth onsaid ends of the'cutters. Y WhatI claim is:'f i a 1. In a device for cutting screW threadS, a cutter-head provided in its forward 2 end portionl' with a slideway extending radially of the cutter-headfa"cutter carrying s'lide engaging sai'd'slideway andgprovided at its" 1 rear side with a slideway extending transversely of the slidesubstantiallyat-"a right angle to the first-mentioned slideway, a

block movable endwise of the second-inentioned slideway and having a hole: extend 7 ing forwardly from the rear face of the second-mentioned slideway, and a shaft havin bearing inthe cutter-"headat'the' rear 7 si e of the cutter-carryingslide and sub-" stantially parallel with "said hole and "provided with a crankrwhich loosely fits said hole and forms a pivotal connection, 'at one side of the axis of1said' shaft,betweenfthe v shaft and said block,

,2. In a device for cutting screwthreads, a cutter-head having a; radially farranged mentioned slideway and has a recess extend-v ing longitudinally ofjthe slide forwardlof the" second-mentioned slideway, a cutterZ'en-L gaging said recess, a screw 'securing tlie put: V a a ter to the slide, a block sl-idabl'e'lendwise of if otalconnection at one-side of the-axis of the said second-mentioned slideway, a d a shaft having bearin in lth Guttgrfheadiat the rear side of the cutter-carrying slideand a provided with a crank operativelyconnected I block substantially ata right angle to sa'ld, Y

lapped by the slide, said slide having a In testimony whereof,Isign the foregoing screw-threaded hole extending rearwardlyspecification, in the presence of two Witfrom the first-mentioned recess t0 the afore nesses. v said second-mentioned slideway, and {the V THOMAS SHEHAN; aforesaid screw having its shank extending t Witnesses: rearwardly from Within the cutter and BASIL F. JOHNSON, threaded into the slide at said threaded hole. I HELEN M. DORER. 

